SAN FRANCISCO -- Bailey Falter pitched so well late last season for the Phillies that he bumped Noah Syndergaard into the bullpen.

Falter said Monday he isn’t sure how to find that version of himself again.

“I do not know,” he said following a 6-3 loss to the Giants at Oracle Park.

Falter might be as frustrated as any Phillies pitcher in recent memory. He allowed eight hits and six unearned runs in 4 1/3 innings against the Giants to fall to 0-7 with a 5.13 ERA. Falter is the first Phillies starter to open a season 0-7 since Jerad Eickhoff in 2017. No Phillies starter has opened a season 0-8 since Kyle Abbott started 0-11 in 1992.

“I’ve changed up my mechanics, I’m trying to throw harder,” Falter said. “Just a whole bunch of things. I’m just going to go back to what got me here.”

Falter went 6-4 with a 3.86 ERA in 20 appearances (16 starts) last season. He replaced Zack Wheeler in the rotation in August, when Wheeler was injured. Falter went 5-0 with a 2.43 in five consecutive starts, so when Wheeler rejoined the team in September, the Phillies kept Falter in the rotation and demoted Syndergaard, whom they acquired in August in a trade.

What was Falter doing then that he isn’t doing now?

“I feel like I’m doing the same thing, honestly,” Falter said.

It is unclear if Falter will make his next start.

“We haven’t talked about anything yet,” Phillies manager Rob Thomson said.

Left-handers Cristopher Sánchez (0-2, 6.14 ERA in Triple-A) and Michael Plassmeyer (1-3, 6.19 ERA in Triple-A) are the only healthy starters on the 40-man roster. Right-hander Noah Skirrow is 4-0 with a 3.52 ERA in six appearances (five starts) with the IronPigs, but he is not on the 40-man. Right-hander Nick Nelson (1.25 ERA in 21 2/3 innings in three levels) reinjured his left hamstring in his last start on Friday, Thomson said. Top prospect Andrew Painter is still recovering from a UCL injury. The Phillies hope he is pitching competitively this summer. No. 2 prospect Mick Abel is 2-2 with a 5.40 ERA in six starts with Double-A Reading. He allowed nine runs in 3 2/3 innings in his last start.

“I would love to,” Falter said about getting more opportunities to start. “But things have to change for that.”

The Phillies tried a couple of things Monday to help Falter. They pushed back his start a few days, hoping to see a boost in velocity. His four-seam fastball averaged 90.4 mph Monday, compared to his season average 90.5 mph. The Phillies also used Connor Brogdon as an opener because Falter had a 7.71 ERA in the first inning this year.

Brogdon needed 28 pitches to get through the first five batters, so Falter faced Brandon Crawford with the bases loaded and two outs. Crawford struck out swinging on a 92.8 mph fastball. It was Falter’s hardest pitch of the season.

The Phillies’ defense failed Falter in the second. Casey Schmitt opened with a single, but Joey Bart hit a ground ball to third baseman Edmundo Sosa. Sosa backed up on the ball, then had trouble getting it out of his glove, costing the Phillies a shot at a double play.

Bryce Johnson singled to center to put runners on first and second. Thairo Estrada then hit a ground ball to Trea Turner, who threw to Bryson Stott at second. But Stott dropped the ball to load the bases. It was Stott’s first error as a second baseman, snapping a franchise-record 84 errorless games to start a Phillies career at second base, according to Elias Sports Bureau.

“Making an error is the thing that makes me the most mad on a baseball field because it's all controllable,” Stott said. “I just dropped it and it kind of spiraled after that. I mean, I don’t like saying one play cost you the game, but a play like that and what ensued after … yeah, it sucked.”

Wilmer Flores hit a fly ball to right fielder Nick Castellanos, who dropped the ball. Castellanos threw out Estrada at second for the second out, but Bart scored to cut the Phillies' lead to 2-1. Falter then allowed a three-run homer to Michael Conforto to hand the Giants a 4-2 lead. Falter gave up a double to J.D. Davis and back-to-back singles to Mitch Haniger and Brandon Crawford to score two more runs and make it 6-2.

All six runs were unearned.